// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic OPP debugfs interface
 *
 * Copyright (C) 2015-2016 Viresh Kumar <viresh.kumar@linaro.org>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/limits.h>
#include <linux/slab.h>

#include "opp.h"

static struct dentry *rootdir;

static void opp_set_dev_name(const struct device *dev, char *name)
{
    if (dev->parent) {
        snprintf(name, NAME_MAX, "%s-%s", dev_name(dev->parent), dev_name(dev));
    } else {
        snprintf(name, NAME_MAX, "%s", dev_name(dev));
    }
}

void opp_debug_remove_one(struct dev_pm_opp *opp)
{
    debugfs_remove_recursive(opp->dentry);
}

static ssize_t bw_name_read(struct file *fp, char __user *userbuf, size_t count, loff_t *ppos)
{
    struct icc_path *path = fp->private_data;
    char buf[64];
    int i;

    i = scnprintf(buf, sizeof(buf), "%.62s\n", icc_get_name(path));

    return simple_read_from_buffer(userbuf, count, ppos, buf, i);
}

static const struct file_operations bw_name_fops = {
    .open = simple_open,
    .read = bw_name_read,
    .llseek = default_llseek,
};

static void opp_debug_create_bw(struct dev_pm_opp *opp, struct opp_table *opp_table, struct dentry *pdentry)
{
    struct dentry *d;
    char name[11];
    int i, ret;

    for (i = 0; i < opp_table->path_count; i++) {
        ret = snprintf(name, sizeof(name), "icc-path-%.1d", i);

        /* Create per-path directory */
        d = debugfs_create_dir(name, pdentry);

        debugfs_create_file("name", S_IRUGO, d, opp_table->paths[i], &bw_name_fops);
        debugfs_create_u32("peak_bw", S_IRUGO, d, &opp->bandwidth[i].peak);
        debugfs_create_u32("avg_bw", S_IRUGO, d, &opp->bandwidth[i].avg);
    }
}

static void opp_debug_create_supplies(struct dev_pm_opp *opp, struct opp_table *opp_table, struct dentry *pdentry)
{
    struct dentry *d;
    int i, ret;

    for (i = 0; i < opp_table->regulator_count; i++) {
        char name[15];

        ret = snprintf(name, sizeof(name), "supply-%d", i);

        /* Create per-opp directory */
        d = debugfs_create_dir(name, pdentry);

        debugfs_create_ulong("u_volt_target", S_IRUGO, d, &opp->supplies[i].u_volt);

        debugfs_create_ulong("u_volt_min", S_IRUGO, d, &opp->supplies[i].u_volt_min);

        debugfs_create_ulong("u_volt_max", S_IRUGO, d, &opp->supplies[i].u_volt_max);

        debugfs_create_ulong("u_amp", S_IRUGO, d, &opp->supplies[i].u_amp);
    }
}

void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
{
    struct dentry *pdentry = opp_table->dentry;
    struct dentry *d;
    unsigned long id;
    char name[25]; /* 20 chars for 64 bit value + 5 (opp:\0) */
    int ret;
    /*
     * Get directory name for OPP.
     *
     * - Normally rate is unique to each OPP, use it to get unique opp-name.
     * - For some devices rate isn't available, use index instead.
     */
    if (likely(opp->rate)) {
        id = opp->rate;
    } else {
        id = _get_opp_count(opp_table);
    }

    ret = snprintf(name, sizeof(name), "opp:%lu", id);

    /* Create per-opp directory */
    d = debugfs_create_dir(name, pdentry);

    debugfs_create_bool("available", S_IRUGO, d, &opp->available);
    debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
    debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
    debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
    debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
    debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate);
    debugfs_create_ulong("clock_latency_ns", S_IRUGO, d, &opp->clock_latency_ns);

    opp_debug_create_supplies(opp, opp_table, d);
    opp_debug_create_bw(opp, opp_table, d);

    opp->dentry = d;
}

static void opp_list_debug_create_dir(struct opp_device *opp_dev, struct opp_table *opp_table)
{
    const struct device *dev = opp_dev->dev;
    struct dentry *d;

    opp_set_dev_name(dev, opp_table->dentry_name);

    /* Create device specific directory */
    d = debugfs_create_dir(opp_table->dentry_name, rootdir);

    opp_dev->dentry = d;
    opp_table->dentry = d;
}

static void opp_list_debug_create_link(struct opp_device *opp_dev, struct opp_table *opp_table)
{
    char name[NAME_MAX];

    opp_set_dev_name(opp_dev->dev, name);

    /* Create device specific directory link */
    opp_dev->dentry = debugfs_create_symlink(name, rootdir, opp_table->dentry_name);
}

/**
 * opp_debug_register - add a device opp node to the debugfs 'opp' directory
 * @opp_dev: opp-dev pointer for device
 * @opp_table: the device-opp being added
 *
 * Dynamically adds device specific directory in debugfs 'opp' directory. If the
 * device-opp is shared with other devices, then links will be created for all
 * devices except the first.
 */
void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
{
    if (opp_table->dentry) {
        opp_list_debug_create_link(opp_dev, opp_table);
    } else {
        opp_list_debug_create_dir(opp_dev, opp_table);
    }
}

static void opp_migrate_dentry(struct opp_device *opp_dev, struct opp_table *opp_table)
{
    struct opp_device *new_dev;
    const struct device *dev;
    struct dentry *dentry;

    /* Look for next opp-dev */
    list_for_each_entry(new_dev, &opp_table->dev_list, node) if (new_dev != opp_dev) break;

    /* new_dev is guaranteed to be valid here */
    dev = new_dev->dev;
    debugfs_remove_recursive(new_dev->dentry);

    opp_set_dev_name(dev, opp_table->dentry_name);

    dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir, opp_table->dentry_name);
    if (!dentry) {
        dev_err(dev, "%s: Failed to rename link from: %s to %s\n", __func__, dev_name(opp_dev->dev), dev_name(dev));
        return;
    }

    new_dev->dentry = dentry;
    opp_table->dentry = dentry;
}

/**
 * opp_debug_unregister - remove a device opp node from debugfs opp directory
 * @opp_dev: opp-dev pointer for device
 * @opp_table: the device-opp being removed
 *
 * Dynamically removes device specific directory from debugfs 'opp' directory.
 */
void opp_debug_unregister(struct opp_device *opp_dev, struct opp_table *opp_table)
{
    if (opp_dev->dentry == opp_table->dentry) {
        /* Move the real dentry object under another device */
        if (!list_is_singular(&opp_table->dev_list)) {
            opp_migrate_dentry(opp_dev, opp_table);
            goto out;
        }
        opp_table->dentry = NULL;
    }

    debugfs_remove_recursive(opp_dev->dentry);

out:
    opp_dev->dentry = NULL;
}

static int opp_summary_show(struct seq_file *s, void *data)
{
    struct list_head *lists = (struct list_head *)s->private;
    struct opp_table *opp_table;
    struct dev_pm_opp *opp;

    mutex_lock(&opp_table_lock);

    seq_puts(s, " device                rate(Hz)    target(uV)    min(uV)    max(uV)\n");
    seq_puts(s, "-------------------------------------------------------------------\n");

    list_for_each_entry(opp_table, lists, node)
    {
        seq_printf(s, " %s\n", opp_table->dentry_name);
        mutex_lock(&opp_table->lock);
        list_for_each_entry(opp, &opp_table->opp_list, node)
        {
            seq_printf(s, "%31lu %12lu %11lu %11lu\n", opp->rate, opp->supplies[0].u_volt, opp->supplies[0].u_volt_min,
                       opp->supplies[0].u_volt_max);
        }
        mutex_unlock(&opp_table->lock);
    }

    mutex_unlock(&opp_table_lock);

    return 0;
}

static int opp_summary_open(struct inode *inode, struct file *file)
{
    return single_open(file, opp_summary_show, inode->i_private);
}

static const struct file_operations opp_summary_fops = {
    .open = opp_summary_open,
    .read = seq_read,
    .llseek = seq_lseek,
    .release = single_release,
};

static int __init opp_debug_init(void)
{
    /* Create /sys/kernel/debug/opp directory */
    rootdir = debugfs_create_dir("opp", NULL);

    debugfs_create_file("opp_summary", 0444, rootdir, &opp_tables, &opp_summary_fops);

    return 0;
}
core_initcall(opp_debug_init);
